My earthen oven dried out over the winter

[asinning]

We built an earth oven last spring and used it all summer long. I haven't built a roof for it yet. Before winter, we gave it one final firing, let it cool down and then covered it with an oil-cloth tarp. I'm in Minnesota where winter lasts 3-4 months and gets as low as -20F (-30C). The walls of our oven are 3" of clayish-earth, a 1" ceramic insulation blanket, and another 3" of the same earth. The inside is hard, like low-fired clay. After a winter covered up, the outside is soft, spongy and dried-out, almost like peat.

We'd like to get started build a roof, but I'm not sure what to do now. Do I need to wet the outside of the oven down and give it a good pressing? What about covering it in wire-mesh and giving it a 3/4" coat of breathable plaster?

Thanks!

[UtahBeehiver]

Not many earth ovens on this forum so responses may limited. Almost all ovens here really either brick or cast refractory. Maybe do a search on cob ovens.

[david s]

We built an earth oven last spring and used it all summer long. I haven't built a roof for it yet. Before winter, we gave it one final firing, let it cool down and then covered it with an oil-cloth tarp. I'm in Minnesota where winter lasts 3-4 months and gets as low as -20F (-30C). The walls of our oven are 3" of clayish-earth, a 1" ceramic insulation blanket, and another 3" of the same earth. The inside is hard, like low-fired clay. After a winter covered up, the outside is soft, spongy and dried-out, almost like peat.

We'd like to get started build a roof, but I'm not sure what to do now. Do I need to wet the outside of the oven down and give it a good pressing? What about covering it in wire-mesh and giving it a 3/4" coat of breathable plaster?

Thanks!

Yes a breathable render coat on the outside should work well but apply it after several fires to ensure you have driven off moisture in the cob. It is really best to build some kind of roof over the oven, just try not to think too much about the extra labour and expense this requires. It is the best solution though. You should not need to wet the outside before applying the breathable render coat, but instead wrap the whole thing in cling wrap to try and hold the moisture in that layer for a few days.

[gastagg]

Hey asinning, I'm in Minneapolis too. Would love to see some pics!